Internal combustion engine



F. RADELET El AL 2,206,332 INTERNAL COMBUSTION ENGINE Filed Nov. 24, 1937 FERNAND RADEL/ET MAX SCHULI MZZM ZATTORNEYS Q INVENTORS Patented July 2, 1940 Fernand Radelet and Max Schul, Brussels,

Belgium; said Schul assignor to said Radelet Application November 24, 1937, Serial No. 176,178 In lBelgium November 28, 1936 14 Claims.

This invention relates to internal combustion engines and it has for its object to provide an exhaust valve device adapted to permit of the mass of burned gases bodily escaping from the cylinder as a pull, and to prevent any backflow 01" said gases into the cylinder,thereby maintaining in the cylinder the vacuum which follows the sudden evacuationof the exhaust gases and making it possible to make use of said vacuum for the suction of fresh gases, which contributes to the attainment of a high output of the engine.

For this purpose, both freely acting valves,

such as ball or flap valves adapted to open under the pressure of the gases and to be closed by spring pressure or otherwise, and positively controlled valves, such as valves or sleeves controlled by cams, eccentrics or the like, have been proposed heretofore. The freely acting valves are operated substantially in the direction of theoutward flow and of the backfiow of the gases; by reason of its inertia, the valve lags somewhat on the backflow of the gases, so that it is violently thrown on its seat by the returning gases and it is liable to vibrate, a tight closure being obtained only after a substantial portion of said gases has found its way into the cylinder; the vibrations moreover speedily wearout the valves of this type. This inconvenience is avoided with positively operated valves, when these are mounted to move transversely of the direction of flow of the gases so that their return movement is not influencedby the return rush of the gases; however, with a positive control the movements of the valve are always too slow and they have to be given such an advance that the valve closes before the end of exhaust, with the result that some of the. burned gases are trapped in the cylinder. a

In accordance with this invention, we use a free exhaust valve adapted to open under the pressure of the outgoing gases and to close when the said pressure ceases, and we arrangesuch valve so that it can only move transversely of the direction of backflow of the gases so that the return rush of the gases does not-impede its closing movementv In one embodiment of our invention, the valve has a bodily sliding movement and a yielding returning means is provided to counterbalance its inertia; we preferably use to this end an adjustable pneumatic device which has a practically instantaneous action. v

In another embodiment, thevalve comprises a flexible metal blade or diaphragm extending substantially parallel to the direction of backfiow 01' the gases, said blade being held at one edge while its other edge is free to move transversely to the said direction and adapted to engage a seat in order to close the exhaust port before the gases return to the cylinder. Such closing movement 5 must be extremely rapid, and this is made possible by the extreme lightness and flexibility of the blade. g

Preferably in both cases the valve, which may comprise a plurality of sections, surrounds-the '10 cylinder ringefashion at the level of a peripheral row of exhaust ports adapted to let out the exhaust as a sudden pufi.

These features and others to be described hereafter will be more fully understood with reference. 16 to the accompanying drawing in which:

Fig. 1 is a vertical section through the wall of a cylinder provided with a sliding exhaust valve, said valve being in the open position.

Fig. 2 is a similar view showing the valve in go the closed position.

Fig. 3 is a sectional elevation showing a valve of the blade type, in the open position.

Fig. 4 is a partial plan view of the valve shown in Fig. 3, the hood away, the cylinder being shown in section through the exhaust ports 3. d

Fig. 5 is a sectional elevation illustrating a modification, as taken on line V-V in Fig. 6.

Fig.6 is a partial plan view illustrating a mod- 30 ification.

Fig.7 is another sectionalelevation of the apparatus of Fig. 6, taken on line VIIVII therein.

In Figs. 1 and 2, which illustrate by way .of example, a valve of the sliding type, I is the 35 cylinder wall, 2 the-piston, and 3 one of a peripheral row of exhaust ports adapted to be uncovered by said piston. The ports 3 open into a passage 4 which is normally closed by the slide valve 5. 0

The valve 5 is mounted for movement transversely of the passage 4 in a guide 5. It is associated with a bellows I connected in a gas-tight mannerthrough a pipe 8 with an air chamber 9 having means such as a threaded plunger I 0 45 for adjusting the air pressure in the bellows so as to balance the weight of the valve 5 in its closed position (Fig. 2). The passage 4 is so shaped that. in this position a wedge-shaped space to, open towards the port 3, is left free between the'upper wall of said passage and the top of valve 5, the passage 4 being closed towards the outside by the side of valve 5.

When port 3 is uncovered by the piston 2 the gas pressurein the cylinder acts through the member ll being partly torn g5 space la on the top of valve 5. depressing the valve which. collapses the bellows 'I and opens the passage 4 through which the burned gases rush out. As soon as the exhaust pressure stops acting, the valve 5 promptly returns to its initial position under the action of the air compressed in bellows I. If the expelled gases tend to flow back into the cylinder before the return movement of the valve is completed, they strike the side of the valve which being positively guided between the surfaces 6 is not affected in its movement transversely of the direction of the gases.

The slide valve 5 may be of any suitable shape or construction. In the example referred to it is shaped as a hollow ring surrounding a peripheral row of ports 3 through which an almost instantaneous exhaust can take place. The passage 4 is in the shape of a peripheral ring, the guide 6 is of annular shape, and the valve rests on a plurality of bellows 'I distributed around the cylinder.

While the provision of a pneumatic control device for returning the valve is of advantage on account of the responsiveness and quick operation of such device, it will be understood that it may be replaced by equivalent means, such as spring means or a hydraulic or electrical device.

In Figs. 3 and 4 which illustrate the second embodiment of our invention, the valve consists of a flexible metal blade or diaphragm ll of annular shape, firmly held at its inner edge adjacent the cylinder wall while its free outer edge is adapted to rest on the edge of a dishshaped member I! forming together with a annular plate It a passage It for the exhaust gases issuing from the ring of ports 3.

The inner edge of the diaphragm II is spaced away from the member I2 by projections l3 provided on the inner edge of said dish shaped member and it is clamped between the annular plate It and said projections which are provided opposite the portions of the cylinder wall I located between adjacent ports 3 (Fig. 4). As shown in Fig. 3, the outer edge of member I! is slightly higher than the top of the projections It so that in its normal closed position the diaphragm H is held under aslight initial tension.

When the piston 2 uncovers the ports 3, the pressure of the gases lifts the free outer edge of the diaphragm II as shown in Fig. 3, and the exhaust gases escape as a puff through the passage l5 between the member I! and the diaphragm the upward movement ofwhich is limited by the hood ll. The sudden exhaust being V ,followed by a vacuum in the cylinder, the diaphragm is immediately returned against its seat, the return movement of its outer edge taking place transversely of the direction of the gases tending to return into the cylinder under the said outer'edge. In order to increase the gas tightness of the jointbetween the diaphragm H and the member [2, a groove l6 may be provided in the outer edge of said-member to provide an oil seal.

In the constructional form shown in Figs. 5, 6 and 7, the diaphragm II is divided into a plurality of segmental-sections by slits II in order to prevent its warping when it is lifted by the gases. Where such slits are provided, the member l2 has projections l8 (mg, 6) extending as far as the outer edge of the diaphragm in order to support the edges of the slit with a gas tight when the valve is in the closed engagement position. The mentioned projections I?! are similar to projections l3, but whereas the latter have but a short radial length, projections I! extend across almost the entire width of the member II, or from its inner edge nearly to its outer edge. As also shown in Figs. 5, 6 and '7 one or more additional blades as It, 20, acting as springs, may be fitted on the diaphragm H in superposed relation and clamped therewith between the projections on member l2 and the annular plate It, to ensure a better tightness and prevent vibration. These blades are also slit at H. g

It will be understood that these additional blades may be omitted and that the invention is not limited to the constructional details shown.'

We claim:-

1. In an internal combustion engine, the combination of a cylinder, a pistonin said cylinder, a peripheral row of exhaust, ports in said 'cylinder adapted to be uncovered by said piston at one end of its stroke, a peripheral outlet passage connected with said ports, a ring-shaped valve normally closing said passage, said valve in its closed position being exposed to and adapted to be operated by pressure in said cylinder, said valve being mounted for movement transversely of said passage.

2. In an internal combustion engine as claimed in claim 1, guiding surfaces for said valve extending substantially at right angles to said peripheral passage, said valve being slidablysupported between said guiding surfaces.

3. In an internal combustion engine as claimed in claim 1, yielding means balancing the weight of said valve for normally holding same in the closed position.

4. In an internal combustion engine as claimed in claim 1, pneumatic means for normally holding said valve in the closed position, and means for adjusting said pneumatic means.

5. In an internal combustion engine, the combination of a cylinder, a piston in said cylinder, a peripheral row, of exhaust ports in said cylinder adapted to.be uncovered by said piston at one end of its stroke, a peripheral radial passage connecting said ports with the atmosphere, 9. ring-shaped valve surrounding said cylinder mounted for sliding movement axially of said cylinder, said valve normally co-operating with a wall of said passage to close said passage, said valve being exposed to and adapted to be opened by pressure in said cylinder, and yielding means for returning said valve to its normal closed position.

6. In an internal combustion engine, the combination of a cylinder, a piston in said cylinder,

shaped diaphragm normally closing said passage, said diaphragm being firmly held at its inner edge, said diaphragm in its closed position being exposed to and adapted to be operated by pressure in said cylinder, the outer edge of said diaphragm being adapted to move trans versely or said passage.

7. In an internal combustion engine as claimed in claim 6, said ring-shaped diaphragm extending in a direction substantially parallel with said passage, the outer edge of said diaphragm cooperating with a dish-shaped wall of said-passage to close said passage.

8. In an internal combustion engine as claimed in claim 6, said passage having a dish-shaped wall with a raised edge, the outer edge of said a peripheral row of exhaust ports in said cylinder 4 diaphragm co-operating with the 'raised edge of said dish-shaped wall to close said passage.

9. In an internal combustion engine as claimed in claim 6, said passage being formed between a dish-shaped member and a hood, projections on said dish-shaped member, the inner edge of said diaphragm being clamped between said projections and said hood.

10. In an internal combustion engine as claimed in claim 6, said diaphragm comprising a plurality of segmental sections separated by radial slits, and means for keeping a fluid-tight engagement with said sections along said slits when the diaphragm is in the closed position.

11. In an internal combustion engine as claimed in claim 6, said passage being formed between a dish-shaped memberand a hood surrounding the cylinder, projections on said dishshaped member, the inner edge of said diaphragm being clamped between said projections and said hood said diaphragm comprising a plurality of segmental sections separated from each other by radial slits, some of the projections on said dishshaped member being adapted to provide a fluidtight engagement with said sections along said slits when the diaphragm is in the closed position.

12. In an internal combustion engine as claimed in claim 6, resilient means for holding said diaphragm in the closed position 13. In an internal combustion engine as claimed in claim 6, said diaphragm comprising a plurality of segmental sections separated by slits, and resilient blades urging said sections towards their closed position.

14 In an internal combustion engine as claimed in claim 6, said passage having a dishshaped wall with an edge forming a seat for said diaphragm, and a groove adjacent said seat forming an oil seal.

F'ERNAND, RADELE'I'.

MAX SCHUL. 

